^Well apparently in ICS you can have downloads running in the background, so it sort of works? Just not like maemo or meego.

You are going to get the best multitasking experience with an N900 or N9. And if you are that in love with the N900 and find that the N9 is lacking, then stick with the N900. I always miss my N900, I love my N9, but it is still no N900.

If you must go android, go with something that has ICS obviously. Nexus is great for that but you can always get an older device with ROMS available for ICS. I would still recommend the GNexus anyway.